Re: [PATCH] fbtft: add tearing signal detect

On Tue, 26 Jan 2021 10:54:41 +0300
Dan Carpenter [off-list ref] wrote:

On Sun, Jan 24, 2021 at 11:35:37PM +0800, Carlis wrote:

quoted

+static irqreturn_t spi_panel_te_handler(int irq, void *data)
+{
+	complete(&spi_panel_te);
+	return IRQ_HANDLED;
+}
+
+static void enable_spi_panel_te_irq(struct fbtft_par *par, bool
enable)  

It quite confused me that enable actually disables.  I always feel
like it's clearer to write these as two separate functions.

quoted

+{
+	static int te_irq_count;
+
+	if (!par->gpio.te) {  

This is always checked in the caller.  And it's when it's NULL that
means it's deliberate so don't print a message.

quoted

+		pr_err("%s:%d,SPI panel TE GPIO not configured\n",
+		       __func__, __LINE__);
+		return;
+	}
+
+	mutex_lock(&te_mutex);
+
+	if (enable) {
+		if (++te_irq_count == 1)
+			enable_irq(gpiod_to_irq(par->gpio.te));
+	} else {
+		if (--te_irq_count == 0)
+			disable_irq(gpiod_to_irq(par->gpio.te));
+	}
+	mutex_unlock(&te_mutex);
+}
+
 /**
  * init_display() - initialize the display controller
  *

@@ -82,6 +117,28 @@ enum st7789v_command {
  */
 static int init_display(struct fbtft_par *par)
 {
+	int rc;
+	struct device *dev = par->info->device;
+
+	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0,

GPIOD_IN);
+	if (par->gpio.te) {  

devm_gpiod_get_index_optional() can return NULL or error pointers.  If
it returns NULL then don't print an error message.  NULL reports are
deliberate.

	par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0,
GPIOD_IN); if (IS_ERR(par->gpio.te)) {
		pr_err("%s:%d, TE gpio not specified\n", __func__,
__LINE__); return PTR_ERR(par->gpio.te);
	}

	if (par->gpio.te) {

quoted

+		init_completion(&spi_panel_te);
+		mutex_init(&te_mutex);
+		rc = devm_request_irq(dev,
+				      gpiod_to_irq(par->gpio.te),
+				     spi_panel_te_handler,
IRQF_TRIGGER_RISING,
+				     "TE_GPIO", par);
+		if (rc) {
+			pr_err("TE request_irq failed.\n");
+			par->gpio.te = NULL;
+		} else {
+
disable_irq_nosync(gpiod_to_irq(par->gpio.te));
+			pr_err("TE request_irq completion.\n");  

Why is this printing an error message if devm_request_irq() succeeds?

quoted

+		}
+	} else {
+		pr_err("%s:%d, TE gpio not specified\n",
+		       __func__, __LINE__);
+	}
 	/* turn off sleep mode */
 	write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
 	mdelay(120);

@@ -137,6 +194,9 @@ static int init_display(struct fbtft_par *par)
 	 */
 	write_reg(par, PWCTRL1, 0xA4, 0xA1);
 
+    /*Tearing Effect Line On*/
+	if (par->gpio.te)
+		write_reg(par, 0x35, 0x00);
 	write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
 
 	if (HSD20_IPS)

@@ -145,6 +205,76 @@ static int init_display(struct fbtft_par *par)
 	return 0;
 }
 
+/*****************************************************************************
+ *
+ *   int (*write_vmem)(struct fbtft_par *par);
+ *
+

*****************************************************************************/
+ +/* 16 bit pixel over 8-bit databus */
+int st7789v_write_vmem16_bus8(struct fbtft_par *par, size_t
offset, size_t len) +{
+	u16 *vmem16;
+	__be16 *txbuf16 = par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int rc, ret = 0;  

Delete one of these "rc" or "rec" variables.

quoted

+	size_t startbyte_size = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "st7789v
---%s(offset=%zu, len=%zu)\n",
+		      __func__, offset, len);
+
+	remain = len / 2;
+	vmem16 = (u16 *)(par->info->screen_buffer + offset);
+
+	if (par->gpio.dc)
+		gpiod_set_value(par->gpio.dc, 1);
+
+	/* non buffered write */
+	if (!par->txbuf.buf)
+		return par->fbtftops.write(par, vmem16, len);
+
+	/* buffered write */
+	tx_array_size = par->txbuf.len / 2;
+
+	if (par->startbyte) {
+		txbuf16 = par->txbuf.buf + 1;
+		tx_array_size -= 2;
+		*(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
+		startbyte_size = 1;
+	}
+
+	while (remain) {
+		to_copy = min(tx_array_size, remain);
+		dev_dbg(par->info->device, "    to_copy=%zu,
remain=%zu\n",
+			to_copy, remain - to_copy);
+
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i] = cpu_to_be16(vmem16[i]);
+
+		vmem16 = vmem16 + to_copy;
+		if (par->gpio.te) {
+			enable_spi_panel_te_irq(par, true);
+			reinit_completion(&spi_panel_te);
+			rc =
wait_for_completion_timeout(&spi_panel_te,
+
msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT));
+			if (rc == 0)
+				pr_err("wait panel TE time out\n");
+		}
+		ret = par->fbtftops.write(par, par->txbuf.buf,
+
startbyte_size + to_copy * 2);  

Line break is whacky.

quoted

+		if (par->gpio.te)
+			enable_spi_panel_te_irq(par, false);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;  

Shouldn't this be "return len;" or something?

quoted

+}
+  

regards,
dan carpenter

OK,i will fix in patch v4

regards,
zhangxuezhi